Special gas mixing bin for lithium battery

Abstract

The present application belongs to the technical field of lithium battery production, and particularly relates to a special gas mixing bin for lithium batteries, which aims at the problems of insufficient mixing uniformity, poor adaptability to different physical property materials and low gas flow energy utilization rate caused by the unified timing work of all nozzles in the existing gas flow mixing equipment, and proposes the following scheme, which comprises a bin body, a mixing cavity for accommodating materials to be mixed is formed in the bin body, and a bin bottom is connected to the bottom of the bin body; a plurality of gas flow nozzles are distributed in different areas of the bottom of the bin body, and the gas outlet directions of the plurality of gas flow nozzles are towards the inside of the bin body; the present application realizes independent pulse control by partition, so that the materials form cross-area convection in the "bubbling - settling - rebubbling" cycle, effectively breaks the stratification interface, and significantly improves the mixing uniformity; at the same time, there is no mechanical shear damage, only local gas supply reduces energy consumption, and the equipment volume can be flexibly expanded to meet the large-scale production demand of lithium batteries.

Description

Technical Field

[0001] This invention relates to the field of lithium battery production technology, and in particular to a special gas mixing chamber for lithium batteries. Background Technology

[0002] In the preparation of positive and negative electrode materials for lithium batteries (especially lithium-ion batteries), the mixing and homogenization of powder raw materials is a key process that determines the consistency and electrochemical performance of the battery. Taking ternary cathode materials as an example, precursors and lithium sources, among other powder materials, need to be fully homogenized in mixing equipment before entering the subsequent sintering stage. The mixing effect directly affects the sintering rate and the structural uniformity of the sintered product.

[0003] Currently, the lithium battery industry mainly uses two types of powder mixing equipment: mechanical mixing equipment and airflow mixing equipment.

[0004] Mechanical mixing equipment (such as ribbon mixers, screw mixers, high-speed mixers, etc.) uses moving parts such as agitators, ribbons, or blades to shear and tumble materials. However, this type of equipment has the following prominent problems:

[0005] (1) Material damage: High-speed moving mechanical parts will shear and impact the powder particles, causing damage to the morphology of the cathode material particles, affecting the specific surface area and loose density of the material.

[0006] (2) Mixing dead corner: There is bound to be a gap between the screw ribbon and the barrel wall. The material in the dead corner cannot be fully mixed. When the material is discharged, it is carried out and seriously affects the uniformity of the material.

[0007] (3) Shaft seal leakage: The shaft seal components of the mechanical mixer are prone to wear and failure after long-term operation, resulting in dust leakage, material loss and environmental pollution;

[0008] (4) Temperature rise and energy consumption: Mechanical transmission friction generates heat, which may cause the material temperature to rise, and at the same time, the power loss is large;

[0009] (5) Limited scale: The existing belt mixer can only reach a maximum of 30 cubic meters, which cannot meet the increasing demand for single-batch mixing in the lithium battery industry.

[0010] Airflow mixing equipment utilizes the energy of compressed air jets to drive powder movement and boiling within a container, achieving material homogenization. Compared to mechanical mixing, airflow mixing has no moving parts, does not damage materials, and allows for larger equipment volumes, and has already found applications in fields such as lithium battery cathode materials. For example, existing patents disclose a technical solution that uses nozzles arranged circumferentially at the bottom of a hopper to alternately pulse compressed air, causing the powder to move continuously within the hopper, thereby achieving blending and homogenization; other patents disclose pulse-type airflow mixers, which have airflow mixing head nozzles at the bottom of a conical mixing hopper, and use solenoid valves to control the pulse injection of high-pressure gas.

[0011] In existing technologies, airflow mixing equipment suffers from problems such as insufficient mixing uniformity due to the uniform timing of all nozzles, poor adaptability to materials with different physical properties, and low airflow energy utilization. To address these issues, we propose a lithium battery-specific air mixing chamber. Summary of the Invention

[0012] The purpose of this invention is to address the shortcomings of existing airflow mixing equipment, such as insufficient mixing uniformity due to the uniform timing of all nozzles, poor adaptability to materials with different properties, and low airflow energy utilization. Therefore, this invention proposes a lithium battery-specific air mixing chamber.

[0013] The technical solution for a lithium battery-specific gas mixing chamber provided in this application is as follows:

[0014] A lithium battery-specific gas mixing chamber, comprising:

[0015] The silo body has an interior forming a mixing chamber for holding the materials to be mixed, and the bottom of the silo body is connected to a silo bottom;

[0016] Multiple airflow nozzles are distributed in different areas at the bottom of the chamber, and the airflow from the multiple airflow nozzles is directed toward the interior of the chamber.

[0017] The gas supply system and control system are connected to multiple gas path branches, which are respectively connected to multiple air flow nozzles.

[0018] Multiple pulse valves are installed on multiple air path branches. The control system is connected to the multiple pulse valves by signal to independently control the opening and closing of the multiple pulse valves, so that the airflow nozzles in different areas can independently perform pulse jet blowing according to the set timing sequence.

[0019] Furthermore, the control system is used to set the pulse frequency, pulse width and blowing pressure of the airflow nozzles in each region according to the physical property parameters, so as to realize differentiated pulse blowing control. The physical property parameters include at least one of particle size distribution, bulk density and angle of repose.

[0020] Furthermore, the bottom of the silo is a conical structure, and a plurality of airflow nozzles are arranged circumferentially along the conical structure and divided into several regional groups along the circumferential direction, each regional group containing at least one of the airflow nozzles.

[0021] Furthermore, the air outlet direction of the airflow nozzle is inclined towards the center of the chamber, so that the ejected airflow forms a fluidization zone from bottom to top within the chamber.

[0022] Furthermore, it also includes a material level detection device and a material composition detection device, and the control system dynamically adjusts the pulse parameters of the airflow nozzles in each area according to the feedback signals from the material level detection device and the material composition detection device.

[0023] Furthermore, a dust collector is provided on the top of the silo to discharge the dust-laden gas generated during the mixing process, and the gas source system includes a gas storage tank and a gas supply valve.

[0024] Furthermore, the gas storage tank supplies compressed gas to each of the gas flow nozzles through the gas supply valve and each gas path branch pipe.

[0025] Furthermore, a discharge valve is provided at the bottom of the silo.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. This solution divides the nozzles and controls the pulse jet independently, which can make differentiated adjustments according to the actual situation of the material in different areas, so that the material forms a "bubbling-settling-re-bubbling" cycle between adjacent areas, which can effectively break the stratification interface caused by differences in particle size and density, and significantly improve the overall mixing uniformity.

[0028] 2. This solution changes the traditional full-area fluidization mode, supplying air only to the local area that needs to be disturbed, thus avoiding the ineffective waste of compressed air in dead or mixed areas, and significantly reducing gas source costs in the long run.

[0029] This invention uses independent pulse control in different zones to enable materials to form cross-regional convection in a "bubbling-settling-re-bubbling" cycle, effectively breaking the stratification interface and significantly improving mixing uniformity. At the same time, it avoids mechanical shear damage, reduces energy consumption by supplying gas only locally, and the equipment volume can be flexibly expanded to meet the needs of large-scale lithium battery production. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a lithium battery-specific gas mixing chamber proposed in this invention;

[0031] Figure 2 This is a nozzle arrangement diagram of a lithium battery-specific gas mixing chamber proposed in this invention.

[0032] Attached reference numerals: 1. Gas storage tank; 2. Gas supply valve; 3. Pulse valve; 4. Hopper; 5. Dust collector; 6. Hopper bottom; 7. Discharge valve. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0034] Example

[0035] Reference Figure 1 and Figure 2 A lithium battery-specific gas mixing chamber, comprising:

[0036] The bin body 4 has a mixing chamber inside for containing the materials to be mixed, and the bottom of the bin body 4 is connected to the bin bottom 6;

[0037] Multiple airflow nozzles are distributed in different areas at the bottom of the chamber 4, and the airflow direction of the multiple airflow nozzles is towards the inside of the chamber 4.

[0038] The gas supply system and control system are connected to multiple gas path branches, which are respectively connected to multiple air flow nozzles.

[0039] Multiple pulse valves 3 are respectively installed on multiple air path branches. The control system is connected to the multiple pulse valves 3 by signal to independently control the opening and closing of the multiple pulse valves 3, so that the airflow nozzles in different areas can independently perform pulse jet blowing according to the set timing sequence.

[0040] In this embodiment, the bottom of the silo 6 is a conical structure, and multiple airflow nozzles are arranged circumferentially along the conical structure and divided into several regional groups along the circumferential direction. Each regional group contains at least one airflow nozzle. The airflow nozzles are inclined towards the center of the silo body 4, so that the ejected airflow forms a fluidized area from bottom to top in the silo body 4. A dust collector 5 is provided at the top of the silo body 4 to discharge the dust-containing gas generated during the mixing process. The air source system includes an air storage tank 1 and an air supply valve 2.

[0041] In this embodiment, a material level detection device and a material composition detection device are also included. The control system dynamically adjusts the pulse parameters of the airflow nozzles in each area according to the feedback signals from the material level detection device and the material composition detection device. The control system is used to set the pulse frequency, pulse width and blowing pressure of the airflow nozzles in each area according to the physical property parameters to achieve differentiated pulse blowing control. The physical property parameters include at least one of particle size distribution, bulk density and angle of repose. The gas storage tank 1 supplies compressed gas to each airflow nozzle through the gas supply valve 2 and each gas branch pipe. The bottom of the bin 6 is provided with a discharge valve 7.

[0042] The implementation principle in this embodiment is as follows: When in use, after the material is put into the mixing chamber from the feed port at the top of the silo 4, the air supply valve 2 is opened, and the compressed gas in the air storage tank 1 is delivered to the air flow nozzles arranged in different areas of the silo bottom 6 through each air path branch pipe. Since the air flow nozzles of each area group correspond to independent air path branch pipes, and each air path branch pipe is equipped with an independently controlled pulse valve 3, the control system can independently switch each pulse valve 3, thereby realizing zoned differentiated pulse jet blowing.

[0043] During the specific mixing process, the control system sets the pulse frequency, pulse width, and injection pressure of the airflow nozzles in each zone according to the physical properties (including particle size distribution, bulk density, and angle of repose) of different components or batches of materials. Each zone performs pulse injection independently according to a preset sequence: when the airflow nozzle in a certain zone opens for pulse injection, compressed gas is injected into the interior of the chamber 4 from the nozzle in that zone. Because the outlet direction of the nozzle is inclined towards the center of the chamber 4, the airflow forms a fluidization zone from bottom to top in the chamber 4, which bubbles and fluidizes the material within the area covered by the zone. The material particles are in a boiling state and surge upward under the action of the airflow. When the nozzle in that zone closes, the material in that zone settles naturally under the action of gravity.

[0044] Adjacent areas are pulse-jet purged sequentially according to a preset time sequence, causing lateral convection and interweaving flow of materials in different areas during the "bubbling-settling-re-bubbling" cycle. The interfaces between different components or batches of materials are repeatedly broken, thereby achieving thorough mixing and homogenization across areas. During this process, the control system dynamically adjusts the pulse parameters of the airflow nozzles in each area based on feedback signals from the material level detection device and the material composition detection device to match the distribution state of materials in the silo in real time. The dust-laden gas generated during the mixing process is filtered by the dust collector 5 at the top of the silo 4 and then discharged. After the materials are evenly mixed, the air supply valve 2 is closed and the discharge valve 7 at the bottom of the silo 6 is opened, and the mixed finished product is discharged from the bottom of the silo 4.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A special gas mixing chamber for lithium batteries, characterized in that: include: The silo body (4) has a mixing chamber inside for holding the materials to be mixed, and the bottom of the silo body (4) is connected to the silo bottom (6). Multiple airflow nozzles are distributed in different areas at the bottom of the chamber (4), and the airflow direction of the multiple airflow nozzles is towards the inside of the chamber (4); The gas supply system and control system are connected to multiple gas path branches, which are respectively connected to multiple air flow nozzles. Multiple pulse valves (3) are respectively installed on multiple air path branches. The control system is connected to the multiple pulse valves (3) by signal to independently control the opening and closing of the multiple pulse valves (3) so that the airflow nozzles in different areas can independently perform pulse jet blowing according to the set time sequence.

2. The lithium battery-specific gas mixing chamber according to claim 1, characterized in that: The control system is used to set the pulse frequency, pulse width and blowing pressure of the airflow nozzles in each region according to the physical property parameters, so as to realize differentiated pulse blowing control. The physical property parameters include at least one of particle size distribution, bulk density and angle of repose.

3. A lithium battery-specific gas mixing chamber according to claim 2, characterized in that: The bottom of the silo (6) is a conical structure, and multiple airflow nozzles are arranged circumferentially along the conical structure and divided into several regional groups along the circumferential direction. Each regional group contains at least one of the airflow nozzles.

4. A lithium battery-specific gas mixing chamber according to claim 3, characterized in that: The air outlet of the air nozzle is inclined toward the center of the chamber (4), so that the airflow forms a fluidization zone from bottom to top in the chamber (4).

5. A lithium battery-specific gas mixing chamber according to claim 4, characterized in that: It also includes a material level detection device and a material composition detection device. The control system dynamically adjusts the pulse parameters of the airflow nozzles in each area based on the feedback signals from the material level detection device and the material composition detection device.

6. A lithium battery-specific gas mixing chamber according to claim 5, characterized in that: The top of the silo (4) is equipped with a dust collector (5) for discharging dust-laden gas generated during the mixing process. The gas source system includes a gas storage tank (1) and a gas supply valve (2).

7. A lithium battery-specific gas mixing chamber according to claim 6, characterized in that: The gas storage tank (1) supplies compressed gas to each of the gas flow nozzles through the gas supply valve (2) and each gas branch pipe.

8. A lithium battery-specific gas mixing chamber according to claim 7, characterized in that: The bottom of the bin (6) is equipped with a discharge valve (7).

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